Screwdrivers used for tightening and loosening threaded screw fasteners are well known and usually consist of a shaft or shank having a handle at one end and a driving tip at the other end for engaging a head of the screw to be driven. Usually the shank and tip are integrally formed from a single piece of steel or other strong metal. The handle is usually formed of plastic, wood or other suitable material and is permanently joined to the shaft. While these screwdrivers work well, certain jobs may require different sized or shaped tips. Several screwdrivers therefore may be needed at a particular job site for driving different type screws encountered. One also may not be certain what particular type of screwdriver is needed for a certain job, but wants to be prepared for the different screws that they may confronted with. This requires that one have on hand a set of multiple, different screwdrivers that can be used for a variety of different jobs. Because each screwdriver has its own handle and shaft, this can be cumbersome, take up a relatively large amount of space, and add to the weight of the screwdrivers that must be carried.
There are screwdrivers that utilize a single handle and shank, but that have a variety of different tips that can be interchanged on the shank. The shaft is usually provided with some type of socket, with the tip being formed as a separate bit or similar device that can be inserted and removed from the socket. Because several different bits are provided with the screwdriver, and they are usually fairly small in size, it is not uncommon that the bits become lost or misplaced. For this reason, the handles on some screwdrivers are hollowed out at the end to provide a storage compartment where the extra bits can be stored. An end cap is usually provided to close off the storage compartment. Because the extra bits are usually held loosely within this compartment, they often tend to rattle around, creating a nuisance to the user. When it is desired to select a bit from the hollowed-out storage area, it is often difficult to see the bits so that the bits must be poured out or otherwise removed from the storage area so that the appropriate bit can be selected. This increases the likelihood that the bits will be dropped and eventually lost.
In some cases, the screwdrivers may be provided with a removable shaft. A different tip can be provided at each end of the removable shank. By removing and inverting the shank, the screwdriver can be provided with at least two different tips. While removable shanks are known, there has not been a screwdriver that has an adjustable length shank that can be effectively secured to the handle.
Other designs provide for a shaft having a tool head at each opposite end. The shaft may be removed, turned around, and reinserted into the handle. Alternatively, the shaft may be slid our of opposite ends of the handle to access and use different heads. However, the mechanics of such dual use tools are often overly complex, increasing the likelihood of failure. In addition, they lack any safety features to protect a user in the case of such a failure of the locking mechanism.
None of the tools of the prior art address these design flaws. It is therefore desirable to provide a dual use tool that has a minimum of moving parts, is durable, reliable and incorporates safety features to prevent and/or mitigate failure of the locking device or other integral mechanisms.